diff --git a/L.Grid.css b/L.Grid.css
old mode 100644
new mode 100755
diff --git a/L.Grid.js b/L.Grid.js
old mode 100644
new mode 100755
index 12cf11c..eae4829
--- a/L.Grid.js
+++ b/L.Grid.js
@@ -100,6 +100,8 @@ L.Grid = L.LayerGroup.extend({
 		var delta = low - high,
 			tick = this._round(delta / ticks, delta);
 
+		if (!tick || !isFinite(tick)) { return []; }
+
 		if (containsZero) {
 			low = Math.floor(low / tick) * tick;
 		} else {
diff --git a/README.md b/README.md
old mode 100644
new mode 100755
diff --git a/example.html b/example.html
old mode 100644
new mode 100755